Type A aortic dissection during transoesophageal echocardiography: a case report

Abstract Background The occurrence of type A aortic dissection (TAAD) during transoesophageal echocardiography (TEE) has only been reported once. We present another case of pre-procedural type B AD with retrograde TAAD or de novo TAAD during the TEE procedure. Case summary An 81-year-old man with a pre-existing infrarenal abdominal aortic aneurysm and highly tortuous aorta was referred to our ward for acute decompensated heart failure (ADHF) with New York Heart Association functional class II. On hospital Day 2, the patient complained of intermittent dull pain over chest and back; ADHF or acute coronary syndrome was suspected. On Day 3, we transferred the patient to the intensive care unit due to ADHF with cardiogenic shock attributed to fluid overload, atrial fibrillation with rapid ventricular response, and severe mitral regurgitation with severely impaired left ventricular ejection fraction. Given the heightened surgical risk, TEE was performed to evaluate the eligibility of mitral transcatheter edge-to-edge repair. The first mid-oesophageal long-axis view showed no evidence of dissection. After 20 min, the same view showed the occurrence of TAAD. Urgent contrast CT confirmed a TAAD extending from the aortic root to the infrarenal abdominal aorta. Due to the prohibitive risk for surgical repair of TAAD, the patient received palliative care and unfortunately passed away on hospital Day 6. Discussion Albeit rare, TAAD could progress or de novo occur during TEE, especially in high-risk patients. Therefore, high alertness during TEE procedures is imperative. Moreover, in patients with AD and poor renal function, the risk of using TEE as an alternative diagnostic modality should be carefully considered.


Background
The occurrence of type A aortic dissection (TAAD) during transoesophageal echocardiography (TEE) has only been reported once.We present another case of pre-procedural type B AD with retrograde TAAD or de novo TAAD during the TEE procedure.
Case summary An 81-year-old man with a pre-existing infrarenal abdominal aortic aneurysm and highly tortuous aorta was referred to our ward for acute decompensated heart failure (ADHF) with New York Heart Association functional class II.On hospital Day 2, the patient complained of intermittent dull pain over chest and back; ADHF or acute coronary syndrome was suspected.On Day 3, we transferred the patient to the intensive care unit due to ADHF with cardiogenic shock attributed to fluid overload, atrial fibrillation with rapid ventricular response, and severe mitral regurgitation with severely impaired left ventricular ejection fraction.Given the heightened surgical risk, TEE was performed to evaluate the eligibility of mitral transcatheter edge-to-edge repair.The first mid-oesophageal long-axis view showed no evidence of dissection.After 20 min, the same view showed the occurrence of TAAD.Urgent contrast CT confirmed a TAAD extending from the aortic root to the infrarenal abdominal aorta.Due to the prohibitive risk for surgical repair of TAAD, the patient received palliative care and unfortunately passed away on hospital Day 6.

Discussion
Albeit rare, TAAD could progress or de novo occur during TEE, especially in high-risk patients.Therefore, high alertness during TEE procedures is imperative.Moreover, in patients with AD and poor renal function, the risk of using TEE as an alternative diagnostic modality should be carefully considered.

Learning points
• To acknowledge that aortic dissection (AD) could progress or occur de novo during a transoesophageal echocardiography (TEE) examination.
• In patients with deteriorated renal function and suspicion of an acute AD, physicians should carefully consider the risk of contrast-induced nephropathy from a CT scan and AD exacerbation during TEE when choosing diagnostic tools.

Introduction
The occurrence of type A aortic dissection (TAAD) during transoesophageal echocardiography (TEE) has only been reported once. 1 The patient received TEE for evaluating left atrial thrombi before catheter ablation, and the hypothesized mechanism was a hypertension surge. 1 This report presents a tragic case with TAAD diagnosed during TEE for assessment of mitral transcatheter edge-to-edge repair (M-TEER) for severe functional mitral regurgitation (MR).

Case presentation
An 81-year-old man visited a local hospital for progressive exertional dyspnoea, abdominal distension, and vomiting for 3 days.According to his family, he was a non-smoker and was diagnosed with heart failure (HF) with reduced ejection fraction 2 years ago.He was admitted for HF exacerbation later in the same year.He denied a past history of hypertension, diabetes, and hyperlipidaemia.Before this admission, he was New York Heart Association (NYHA) functional class II.

Figure 1
Figure 1 Transoesophageal echocardiogram (TEE) images.(A) The first mid-oesophageal long-axis view (123°) showed ascending aorta of 41 mm without evidence of dissection.(B) Twenty minutes after the probe insertion, the mid-oesophageal view (107°) revealed the presence of type A aortic dissection.The arrow indicated the dissected intimal layer.

Figure 4
Figure 4 Computed tomography (CT) images before and after the transoesophageal echocardiogram (TEE) procedure.(A) The pre-procedural CT at the same level of suspected intimal flap, no signs of the dissection was noticed.(B) The axial view of the post-procedural CT showed the location of the suspected intimal flap, where contrast enhancement in the false lumen can be noticed (arrow).(C ) Coronal view of the type A aortic dissection.(D) Sagittal view of the type A aortic dissection.